Romantic relationships are central in adolescents' social life and emotional experiences, and have important implications for socio-emotional adjustment and health. Surprisingly little work, however, has been done on these relationships. In our current grant, we examined the pattern of relations among adolescents' romantic relationships, their cognitive views of different close relationships, and psychosocial adjustment. Specifically. 197 high school seniors were interviewed thrice about their romantic relationships, friendships, and relationships with parents, completed questionnaires, and were observed with partners. Significant links were found among their relationships, views, and adjustment. These results are encouraging, but are limited by their cross-sectional nature. We propose to extend this research up by conducting a longitudinal study to a) describe the developmental course of romantic views and relationships, b) to examine how romantic views and relationships are related, c) to examine how they are related to views and qualities of other relationships, and d) to examine the links with sexual behavior and psycho-social adjustment. Multi-agent, multi-method data will be gathered from a cohort of 200 tenth grade adolescents with three subsequent waves collected yearly. In the first wave, adolescents will be observed interacting with their romantic partner, a close friend, and mother; they will be interviewed three times to assess their views of these close relationships. In the following waves, they will be interviewed about romantic relationships and observed with their partners. Questionnaires about relationships, sexual behavior, and adjustment will be gathered from multiple agents at all waves. Latent growth curve analyses will examine the predictors and outcomes of individual romantic and sexual development. The findings will have important implications for understanding adolescents' romantic and sexual behavior and the health problems associated with them.